The analyses of a text #1

The protagonist, Philip, who was born with a club foot, moved in with his uncle Mr. Carey, the Vicar of Blackstable after his mother's death.
He came to Paris to become a painter.

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"Look, here's a Monet," she said. "It's the Gare St. Lazare."
"But the railway lines aren't parallel," said Philip.
"What does that matter?" she asked, with a haughty air.
Philip felt ashamed of himself. Fanny Price had picked up the glib chatter of the studios and had no difficulty in impressing Philip with the extent of her knowledge. She proceeded to explain the pictures to him, superciliously but not without insight, and showed him what the painters had attempted and what he must look for. She talked with much gesticulation of the thumb, and Philip, to whom all she said was new, listened with profound but bewildered interest. Till now he had worshipped Watts and Burne-Jones. The pretty colour of the first, the affected drawing of the second, had entirely satisfied his aesthetic sensibilities. Their vague idealism, the suspicion of a philosophical idea which underlay the titles they gave their pictures, accorded very well with the functions of art as from his diligent perusal of Ruskin he understood it; but here was something quite different: here was no moral appeal; and the contemplation of these works could help no one to lead a purer and a higher life. He was puzzled.
[Of Human Bondage by Somerset Maugham]
1. I'd like to know what "of the first" means.
2. And I'd like to know "he understood it" is parenthetical.
Thank you in advance for your help